Abstract：
Microplastics (MPs) are widely detected in wetlands as emerging pollutants of global concern. Co-occurrence of MPs and trace metals in wetlands is common and the vector effects of MPs on other environmental pollutants have been increasingly reported. However, the interaction of different MPs and trace metals under environmentally realistic conditions is not well understood. Here, we investigated the adsorption capacity of MPs for metals under simulated conditions of Poyang Lake wetlands in Jiang Xi, China, a Ramsar site of international importance for conservation and sustainable use. ICP-MS was used to quantify the amount of adsorbed metals onto different types of MPs. SEM-EDS and micro-FTIR were used to examine the morphological and chemical characteristics of MPs before and after metal adsorption. The influence of internal (polymer types and particle sizes of MPs) and external factors (water pH values, organic matters, ion strength, and sediment) on metal adsorption was systematically investigated. Metal adsorption equilibrium was most achieved at 72 h. The adsorption capacity of MP types to metal ions tended to decrease as PP > PE > PS, and the amount of adsorbed metals decreased as Cu > Pb > Cd. The amount of adsorbed metals generally decreased with the increase of particle size of MPs. With the increase of water pH and K+ strength, the adsorption of metals by MPs showed an increasing and then decreasing trend; the adsorption capacity of MPs increased with the increase of fulvic acid. Under the simulated sedimentary conditions, the adsorption of different metals by MPs also tended to be Cu > Pb > Cd, which was mainly determined by metal concentrations in the sediments collected in situ. The results of this study improve our understanding of metal-MP interaction under simulated environmental conditions, shedding new light on the environmental behavior of MPs and metals in wetlands.
摘要：
微塑料（MPs）作为全球关注的新兴污染物在湿地中被广泛发现。湿地中MPs和痕量金属的共存现象很普遍，越来越多的报道了MPs对其他环境污染物的媒介影响。然而,在环境现实条件下，不同的MP和痕量金属的相互作用还没有得到很好的理解。这里,我们研究了在江西鄱阳湖湿地模拟条件下MPs对金属的吸附能力，中国,对保护和可持续利用具有国际重要性的拉姆萨尔遗址。ICP-MS用于定量不同类型的MP上吸附的金属的量。SEM-EDS和显微FTIR用于检测金属吸附前后MPs的形态和化学特性。内部（聚合物类型和MPs的粒径）和外部因素（水的pH值，有机物,离子强度,和沉积物）对金属吸附进行了系统研究。金属吸附平衡在72h达到最大。随着PP>PE>PS，MP类型对金属离子的吸附能力趋于降低。吸附金属的量随着Cu>Pb>Cd而减少。随着MPs粒径的增大,金属的吸附量总体上呈下降趋势。随着水pH值和K+强度的增加,MPs对金属的吸附量呈先增加后降低的趋势;MPs的吸附量随着富里酸的增加而增加。在模拟沉积条件下,MPs对不同金属的吸附也趋于Cu>Pb>Cd,这主要取决于原位收集的沉积物中的金属浓度。这项研究的结果提高了我们对模拟环境条件下金属-MP相互作用的理解，为湿地中MP和金属的环境行为提供了新的思路。
